Torque distribution method and apparatus for distributed drive, and vehicle and medium

Abstract

A torque distribution method for distributed drive, the method comprising: when a driving mode of a vehicle is a traction recovery mode, determining a first target required torque of a target axle provided with an EDS, and a first target torque and an allowable maximum drive torque of each wheel corresponding to the target axle; when a first wheel of the target axle slips, calculating a second target required torque of the target axle; if a second wheel meets a preset condition, on the basis of the second target required torque of the target axle, the torque capacity of the EDS, the first target torque of each wheel corresponding to the target axle, and a maximum available electric-motor torque, calculating a second target torque of each wheel corresponding to the target axle; and determining a final target requested electric-motor torque of each wheel. The method can ensure that the tractive force is used to the greatest extent. In addition, the present invention further relates to a torque distribution control apparatus for distributed drive, and a vehicle, a computer-readable storage medium, a chip, a computer program product and a computer program.

Description

Distributed drive torque distribution methods, devices, vehicles and media

[0001] This application claims priority to Chinese Patent Application No. 202411923212.7, filed on December 25, 2024, entitled "Method, Apparatus, Vehicle and Medium for Distributed Drive Torque Distribution", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to, but is not limited to, the field of vehicle technology, and in particular to a distributed drive torque distribution method, device, vehicle, and medium. Background Technology

[0003] With the development of vehicle technology, vehicle drive modes are no longer limited to centralized drive. More vehicles are beginning to adopt distributed drive for vehicle control. Distributed drive is a new type of power system in which four motors independently drive four wheels. It can arbitrarily distribute wheel torque according to actual road conditions and vehicle driving status, realizing the driving and braking force control of individual wheels. The control system can be implemented through software. Therefore, the off-road mode of the four-motor drive type will not cause loss of control due to the limitations of the mechanical structure.

[0004] Currently, the drive torque distribution method for distributed electric vehicles is usually a relatively simple one, such as the torque equalization method, which distributes the torque requested by the driver equally to the four wheels, with each wheel receiving 1 / 4 of the torque requested by the driver.

[0005] However, if any wheel slips, there will be a problem of wasted power. Summary of the Invention

[0006] This application provides a distributed drive torque distribution method, device, vehicle, and medium to solve the problem of power waste in the prior art when wheel slippage occurs.

[0007] In a first aspect, embodiments of this application provide a torque distribution method for a distributed drive, comprising:

[0008] When the vehicle's driving mode is in the escape mode, the first target required torque of the target axle with EDS, the first target torque of each wheel corresponding to the target axle, and the maximum allowable driving torque are determined based on the accelerator pedal opening and the overall vehicle status parameters.

[0009] When the first wheel of the target axle slips, the second target torque of the target axle is calculated based on the first target torque requirement of the target axle and the maximum allowable driving torque of each wheel corresponding to the target axle.

[0010] If the second wheel meets the preset conditions, then the second target torque of each wheel corresponding to the target axle is calculated based on the second target required torque of the target axle, the torque capacity of the EDS, the first target torque of each wheel corresponding to the target axle, and the maximum available torque of the motor. The preset conditions are related to the second target required torque of the target axle, and the second wheel is located on the target axle.

[0011] For each wheel corresponding to the target axle, the final target torque of the motor for the wheel is determined based on the second target torque of the wheel, the initial target torque of the motor, the yaw torque, and the available torque of the motor after power limiting the wheel. The initial target torque of the motor is the target torque of the motor obtained after wheel slip control.

[0012] In one possible design, calculating the second target torque requirement of the target axle based on the first target torque requirement of the target axle and the maximum allowable driving torque of each wheel corresponding to the target axle includes:

[0013] Add the maximum allowable driving torque of the first wheel and the maximum allowable driving torque of the second wheel to obtain the sum of the maximum allowable driving torques;

[0014] The minimum value between the first target required torque of the target axle and the maximum allowable driving torque is determined as the second target required torque of the target axle.

[0015] In one possible design, calculating the second target torque for each wheel corresponding to the target axle, based on the second target torque requirement of the target axle, the torque capacity of the EDS, the first target torque for each wheel corresponding to the target axle, and the maximum available torque of the motor, includes:

[0016] The difference between the second target required torque of the target axle and the first target torque of the second wheel is determined as the first torque difference of the first wheel.

[0017] The minimum value among the first torque difference of the first wheel, the torque capacity of the EDS, and the maximum available torque of the motor of the first wheel is determined as the second target torque of the first wheel.

[0018] The difference between the second target required torque of the target axle and the second target torque of the first wheel is determined as the first torque difference of the second wheel;

[0019] The minimum value among the first torque difference of the second wheel, the torque capacity of the EDS, and the maximum available torque of the motor of the second wheel is determined as the second target torque of the second wheel.

[0020] In one possible design, determining the final target motor torque for each wheel corresponding to the target axle, based on the wheel's second target torque, initial target motor torque request, yaw torque, and the available motor torque after power limiting the wheel, includes:

[0021] The minimum value among the second target torque of the first wheel, the initial target torque requested by the motor, the yaw torque, and the available torque of the motor after power limiting the first wheel is determined as the final target torque requested by the motor of the first wheel.

[0022] The minimum value among the second target torque of the second wheel, the initial target torque requested by the motor, the yaw torque, and the available torque of the motor after power limiting the second wheel is determined as the final target torque requested by the motor of the second wheel.

[0023] In one possible design, determining the first target required torque of the target axle equipped with EDS, the first target torque of each wheel corresponding to the target axle, and the permissible maximum drive torque based on the accelerator pedal opening and overall vehicle state parameters includes:

[0024] For each wheel corresponding to the target axle, the utilization adhesion coefficient and slip ratio of the wheel are calculated based on the vehicle speed, wheel speed, vertical load, and driving force.

[0025] Based on the accelerator pedal opening, the vehicle's overall basic parameters, the input axle load / wheel load parameters, the tire rolling radius of each wheel, the wheel track, the distance from the center of gravity to the axle where the wheel is located, and the wheel's rotation angle, calculate the first target torque required for the target axle and the first target torque for each wheel corresponding to the target axle.

[0026] The allowable maximum driving torque of the wheel is determined based on the road surface type, the wheel's coefficient of adhesion, slip ratio, preset maximum load, tire rolling radius, and safety factor. The safety factor is determined based on the coefficient of adhesion.

[0027] In one possible design, calculating the coefficient of adhesion and slip ratio of the wheel based on the vehicle speed, wheel speed, vertical load, and driving force includes:

[0028] Calculate the slip ratio of the wheel based on the vehicle speed and the wheel speed;

[0029] The coefficient of adhesion of the wheel is calculated based on the driving force and vertical load of the wheel.

[0030] In one possible design, the calculation of the first target torque requirement for the target axle and the first target torque for each wheel corresponding to the target axle, based on the accelerator pedal opening, the vehicle's overall basic parameters, the input axle load / wheel load parameters, the tire rolling radius of each wheel, the wheel track, the distance from the center of gravity to the axle where the wheel is located, and the wheel's steering angle, includes:

[0031] Based on the vehicle's overall basic parameters and the accelerator pedal opening, determine the vehicle's total target torque requirement and total target yaw torque.

[0032] Calculate the torque distribution ratio of the target axle based on the input axle load / wheel load parameters;

[0033] The yaw torque conversion coefficient of the wheel is calculated based on the tire rolling radius, wheel track, distance from the center of gravity to the axle of the wheel corresponding to each wheel of the target axle, and the turning angle of the wheel.

[0034] Based on the total target torque requirement, the total target yaw torque, the torque distribution ratio of the target axle, and the yaw torque conversion coefficient of each wheel corresponding to the target axle, calculate the first target torque requirement of the target axle and the first target torque of each wheel corresponding to the target axle.

[0035] In one possible design, determining the allowable maximum driving torque of the wheel based on the road surface type, the wheel's coefficient of adhesion, slip ratio, preset maximum load, tire rolling radius, and safety factor includes:

[0036] Based on the road surface type, a target slip ratio is determined for the corresponding road surface type, wherein the target slip ratio is the slip ratio corresponding to the maximum utilization coefficient of adhesion for the road surface type.

[0037] The allowable maximum driving force of the wheel is determined based on the wheel slip ratio, the target slip ratio, the adhesion coefficient, and the preset maximum load.

[0038] The allowable maximum driving torque of the wheel is determined based on the wheel's maximum permissible driving force, the tire's rolling radius, and the safety factor.

[0039] In one possible design, determining the allowable maximum driving torque of the wheel based on the road surface type, the wheel's coefficient of adhesion, slip ratio, preset maximum load, tire rolling radius, and safety factor includes:

[0040] Based on the road surface type, a target slip ratio is determined for the corresponding road surface type, wherein the target slip ratio is the slip ratio corresponding to the maximum utilization coefficient of adhesion for the road surface type.

[0041] The allowable maximum driving force of the wheel is determined based on the wheel slip ratio, the target slip ratio, the adhesion coefficient, and the preset maximum load.

[0042] The allowable maximum driving torque of the wheel is determined based on the wheel's maximum permissible driving force, the tire's rolling radius, and the safety factor.

[0043] In one possible design, the preset conditions include that the maximum available torque of the motor of the second wheel is less than the second target requirement of the target axle, and the second target requirement of the target axle is less than the maximum permissible drive torque of the second wheel.

[0044] In one possible design, the method further includes:

[0045] In response to the user's selection of an escape mode via the HMI, the vehicle's driving mode is adjusted to escape mode.

[0046] In one possible design, the method further includes:

[0047] Based on the final motor target requested torque for each wheel corresponding to the target axle, a control signal is sent to the motor controller of each wheel.

[0048] Secondly, embodiments of this application provide a distributed drive torque distribution control device, comprising:

[0049] The first determining module is configured to determine the first target required torque of the target axle with EDS, the first target torque of each wheel corresponding to the target axle, and the maximum allowable driving torque based on the accelerator pedal opening and the overall vehicle status parameters when the vehicle's driving mode is in the escape mode.

[0050] The first calculation module is configured to calculate the second target torque of the target axle when the first wheel of the target axle slips, based on the first target torque requirement of the target axle and the maximum allowable driving torque of each wheel corresponding to the target axle.

[0051] The second calculation module is configured to calculate the second target torque of each wheel corresponding to the target axle based on the second target required torque of the target axle, the torque capacity of the EDS, the first target torque of each wheel corresponding to the target axle, and the maximum available torque of the motor if the second wheel meets the preset conditions. The preset conditions are related to the second target required torque of the target axle, and the second wheel is located on the target axle.

[0052] The second determining module is configured to determine the final motor target requested torque of each wheel corresponding to the target axle, based on the second target torque of the wheel, the initial motor target requested torque, the yaw torque, and the available motor torque after power limiting the wheel. The initial motor target requested torque is the motor target requested torque obtained after wheel slip control.

[0053] In one possible design, the first computing module is specifically configured as follows:

[0054] Add the maximum allowable driving torque of the first wheel and the maximum allowable driving torque of the second wheel to obtain the sum of the maximum allowable driving torques;

[0055] The minimum value between the first target required torque of the target axle and the maximum allowable driving torque is determined as the second target required torque of the target axle.

[0056] In one possible design, the second computing module is specifically configured as follows:

[0057] The difference between the second target required torque of the target axle and the first target torque of the second wheel is determined as the first torque difference of the first wheel.

[0058] The minimum value among the first torque difference of the first wheel, the torque capacity of the EDS, and the maximum available torque of the motor of the first wheel is determined as the second target torque of the first wheel.

[0059] The difference between the second target required torque of the target axle and the second target torque of the first wheel is determined as the first torque difference of the second wheel;

[0060] The minimum value among the first torque difference of the second wheel, the torque capacity of the EDS, and the maximum available torque of the motor of the second wheel is determined as the second target torque of the second wheel.

[0061] In one possible design, the second determining module is specifically configured as follows:

[0062] The minimum value among the second target torque of the first wheel, the initial target torque requested by the motor, the yaw torque, and the available torque of the motor after power limiting the first wheel is determined as the final target torque requested by the motor of the first wheel.

[0063] The minimum value among the second target torque of the second wheel, the initial target torque requested by the motor, the yaw torque, and the available torque of the motor after power limiting the second wheel is determined as the final target torque requested by the motor of the second wheel.

[0064] In one possible design, the first determining module is specifically configured as follows:

[0065] For each wheel corresponding to the target axle, the utilization adhesion coefficient and slip ratio of the wheel are calculated based on the vehicle speed, wheel speed, vertical load, and driving force.

[0066] Based on the accelerator pedal opening, the vehicle's overall basic parameters, the input axle load / wheel load parameters, the tire rolling radius of each wheel, the wheel track, the distance from the center of gravity to the axle where the wheel is located, and the wheel's rotation angle, calculate the first target torque required for the target axle and the first target torque for each wheel corresponding to the target axle.

[0067] The allowable maximum driving torque of the wheel is determined based on the road surface type, the wheel's coefficient of adhesion, slip ratio, preset maximum load, tire rolling radius, and safety factor. The safety factor is determined based on the coefficient of adhesion.

[0068] In one possible design, the first determining module is specifically configured as follows:

[0069] Calculate the slip ratio of the wheel based on the vehicle speed and the wheel speed;

[0070] The coefficient of adhesion of the wheel is calculated based on the driving force and vertical load of the wheel.

[0071] In one possible design, the first determining module is specifically configured as follows:

[0072] Based on the vehicle's overall basic parameters and the accelerator pedal opening, determine the vehicle's total target torque requirement and total target yaw torque.

[0073] Calculate the torque distribution ratio of the target axle based on the input axle load / wheel load parameters;

[0074] The yaw torque conversion coefficient of the wheel is calculated based on the tire rolling radius, wheel track, distance from the center of gravity to the axle of the wheel corresponding to each wheel of the target axle, and the turning angle of the wheel.

[0075] Based on the total target torque requirement, the total target yaw torque, the torque distribution ratio of the target axle, and the yaw torque conversion coefficient of each wheel corresponding to the target axle, calculate the first target torque requirement of the target axle and the first target torque of each wheel corresponding to the target axle.

[0076] In one possible design, the first determining module is specifically configured as follows:

[0077] Based on the road surface type, a target slip ratio is determined for the corresponding road surface type, wherein the target slip ratio is the slip ratio corresponding to the maximum utilization coefficient of adhesion for the road surface type.

[0078] The allowable maximum driving force of the wheel is determined based on the wheel slip ratio, the target slip ratio, the adhesion coefficient, and the preset maximum load.

[0079] The allowable maximum driving torque of the wheel is determined based on the wheel's maximum permissible driving force, the tire's rolling radius, and the safety factor.

[0080] In one possible design, the distributed drive torque distribution control device further includes a control module configured as follows:

[0081] If the second wheel meets the preset conditions, then control the EDS to enter the locking mode;

[0082] If the wheel of the target axle exits the wheel slip control, or the reference speed of the vehicle is greater than the preset speed, or the steering angle of the vehicle is greater than the preset angle, or any motor of the vehicle malfunctions, then the EDS is controlled to exit the lock-up mode.

[0083] In one possible design, the preset conditions include that the maximum available torque of the motor of the second wheel is less than the second target requirement of the target axle, and the second target requirement of the target axle is less than the maximum permissible drive torque of the second wheel.

[0084] In one possible design, the distributed drive torque distribution control device further includes an adjustment module, configured as follows:

[0085] In response to the user's selection of the traction mode via the human-machine interface (HMI), the driving mode of the vehicle is adjusted to the traction mode.

[0086] In one possible design, the distributed drive torque distribution control device further includes a transmitting module, configured as follows:

[0087] Based on the final motor target requested torque for each wheel corresponding to the target axle, a control signal is sent to the motor controller of each wheel.

[0088] Thirdly, embodiments of this application provide a vehicle, including: a vehicle body, a vehicle controller, a motor for each wheel, a memory, and computer program instructions stored in the memory and executable on the vehicle controller. When the vehicle controller executes the computer program instructions, it is used to implement the methods provided in the first aspect and various possible designs.

[0089] Fourthly, embodiments of this application may provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a vehicle controller, are used to implement the methods provided in the first aspect and various possible designs.

[0090] Fifthly, embodiments of this application provide a computer program product, including a computer program that, when executed by a vehicle controller, is used to implement the methods provided in the first aspect and various possible designs.

[0091] In a sixth aspect, embodiments of the present invention provide a chip, the chip including a memory and a vehicle controller, the memory storing code and data, the memory being coupled to the vehicle controller, the vehicle controller running a program in the memory causing the chip to implement the methods provided in the first aspect and various possible designs.

[0092] In a seventh aspect, embodiments of the present invention provide a computer program, which, when executed by a vehicle controller, is used to implement the methods provided in the first aspect and various possible designs.

[0093] This application provides a distributed drive torque distribution method, apparatus, vehicle, and medium. The method includes: when the vehicle's driving mode is in escape mode, determining a first target demand torque for a target axle equipped with an EDS, a first target torque for each wheel corresponding to the target axle, and a maximum allowable driving torque based on the accelerator pedal opening and overall vehicle state parameters. Then, when the first wheel of the target axle slips, calculating a second target demand torque for the target axle based on the first target demand torque and the maximum allowable driving torque for each wheel corresponding to the target axle. If the second wheel meets preset conditions, calculating a second target torque for each wheel corresponding to the target axle based on the second target demand torque of the target axle, the torque capacity of the EDS, the first target torque for each wheel corresponding to the target axle, and the maximum available torque of the motor. For each wheel corresponding to the target axle, determining the final target demand torque of the motor based on the wheel's second target torque, the initial target motor demand torque, the yaw torque, and the available motor torque after power limiting the wheel. The initial target torque requested by the motor is the target torque requested by the motor obtained after wheel slippage control. The preset condition is related to the second target torque requirement of the target axle, and the second wheel is located on the target axle. In this technical solution, when the first wheel of the target axle slips and the second wheel meets the preset condition, the EDS is controlled to enter the lock-up mode so that the unusable motor torque capacity of the first wheel can be transferred to the second wheel, thereby ensuring that the power is maximized.

[0094] The above is an overview of the subject matter described in detail herein, and this overview is not intended to limit the scope of the claims. Attached Figure Description

[0095] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0096] Figure 1 is a schematic diagram of a distributed drive system topology;

[0097] Figure 2 is a flowchart illustrating an embodiment of the torque distribution method for distributed drive provided in this application.

[0098] Figure 3 is a schematic diagram of another topology for distributed drive power;

[0099] Figure 4 is a schematic diagram of the position of EDS in a distributed drive configuration with one front and two back.

[0100] Figure 5 is a schematic diagram of a scenario where the right rear wheel of a vehicle is stuck;

[0101] Figure 6 is a flowchart illustrating Embodiment 2 of the distributed drive torque distribution method provided in this application.

[0102] Figure 7 is a graph showing the relationship between slip ratio and adhesion coefficient provided in the embodiments of this application.

[0103] Figure 8 is a structural diagram of a conventionally powered off-road vehicle;

[0104] Figure 9 is a flowchart illustrating Embodiment 3 of the distributed drive torque distribution method provided in this application.

[0105] Figure 10 is a flowchart illustrating Embodiment 4 of the distributed drive torque distribution method provided in this application.

[0106] Figure 11 is a schematic diagram of the structure of the distributed drive torque distribution control device provided in the embodiment of this application.

[0107] The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0108] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0109] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, use and processing of the relevant data must comply with relevant laws, regulations and standards, and corresponding operation entry points are provided for users to choose to authorize or refuse.

[0110] Before introducing the embodiments of this application, the application background of the embodiments of this application will be explained first:

[0111] Figure 1 is a schematic diagram of a distributed drive system topology. As shown in Figure 1, the distributed drive vehicle is equipped with a power battery to power four electric drive systems. The four electric drive systems independently drive the four wheels, so that each wheel has an independent power source and can distribute wheel torque in real time according to road conditions and vehicle driving status.

[0112] Distributed drive vehicles can achieve intelligent torque distribution between the front and rear axles and between the left and right wheels. However, because the driving forces of the left and right wheels on the same axle are completely decoupled, when one wheel slips, the driving torque of the slipping wheel is limited, while the driving torque of the other wheels remains unchanged. In other words, in the example above, if a wheel on one side of the same axle slips, the torque distribution between the slipping wheel and the high-tether wheel on that axle is approximately 0:25%. This limits the maximum capacity of the entire vehicle's drive system, resulting in wasted power.

[0113] This application provides a distributed drive torque distribution method, which sets an electronic limited-slip differential (EDS) on the axle of the vehicle. When it is determined that the vehicle is in an off-road mode, there is wheel slippage, and certain preset conditions are met, the EDS is locked to transfer the motor torque capability of the slipping wheel to the high-attachment wheel on the same axle, thereby maximizing the use of the coaxial drive capability, solving the problem of power waste, and helping the vehicle get out of trouble.

[0114] The technical solution of this application will now be described in detail through specific embodiments.

[0115] It should be noted that the following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0116] Figure 2 is a flowchart illustrating a first embodiment of the distributed drive torque allocation method provided in this application. As shown in Figure 2, the distributed drive torque allocation method may include the following steps:

[0117] S21. When the vehicle's driving mode is in the escape mode, determine the first target required torque of the target axle with EDS, the first target torque of each wheel corresponding to the target axle, and the maximum allowable driving torque based on the accelerator pedal opening and the overall vehicle status parameters.

[0118] The execution subject of this application embodiment is a vehicle, and the driving form of the vehicle is distributed drive. The distributed drive can be as shown in Figure 1, or as shown in Figure 3, or as a distributed drive configuration of one in front and two in the back, or two in front and one in the back.

[0119] Figure 3 illustrates another topology of distributed drive system. As shown in Figure 3, a power battery is located in the middle of the vehicle to power three electric drive systems. One drive system drives the two wheels on the front axle, while the remaining two electric drive systems independently drive the two wheels on the rear axle.

[0120] It should be understood that if the distributed drive is as shown in Figure 1, then an EDS can be set on the front axle and the rear axle of the vehicle respectively, that is, both the front axle and the rear axle are target axles; if the distributed drive is as shown in Figure 3, then an EDS can be set on the rear axle, that is, the rear axle of the vehicle is the target axle.

[0121] Figure 4 is a schematic diagram of the position of the EDS in a distributed drive configuration with one axle in the front and two in the rear. As shown in Figure 4, based on Figure 3, one EDS is installed on the rear axle of the vehicle.

[0122] In practical applications, drivers can operate the Human-Machine Interface (HMI) to select the vehicle's driving mode.

[0123] In one alternative implementation, the vehicle's driving mode is adjusted to the traction mode in response to the user's traction mode selection operation via the HMI.

[0124] In one specific implementation, the HMI can display controls corresponding to various driving modes for the user. When the driver finds the vehicle stuck in low-traction conditions (potholes, mud, rocks, sand, or deep snow), they can click the control corresponding to the escape mode in the HMI. The vehicle will then respond to the user's click on the control and adjust its driving mode to escape mode. It should be understood that the user's click on the control corresponding to the escape mode is the user's selection of the escape mode through the HMI.

[0125] Because the traction control mode optimizes engine parameters such as fuel injection and ignition to prevent sudden power interruption or fluctuation, it can interact with the driver in some low-traction conditions to adjust the vehicle to the most suitable traction control mode, helping the vehicle to pass through complex road sections more stably.

[0126] It should be understood that the off-road modes include Intelligent Terrain Setting (ATS) and Low-Speed ​​4WD (4L).

[0127] in:

[0128] a) ATS is suitable for all-terrain conditions, such as rock, mud, and sand. The vehicle intelligently determines the current road surface type and automatically adjusts its power output through dynamics fusion algorithms and visual perception algorithms.

[0129] b) In 4L mode, the vehicle can achieve high torque output, which is suitable for the high torque extrication needs of complex road conditions.

[0130] It should be understood that the first target torque of each wheel corresponding to the target axle is the target torque obtained by the vehicle based on the accelerator pedal opening after the driver presses the accelerator pedal, and the first target torque distribution of the left and right motors of the target axle is obtained by combining the basic parameters of the vehicle. The first target torque of the target axle is the sum of the first target torques of the left and right wheels corresponding to the target axle.

[0131] It should be understood that the wheel corresponding to the target axle is the wheel installed on the target axle.

[0132] It should be understood that the specific implementation process and principle of this step will be explained in detail in the embodiment shown in Figure 6, and will not be repeated here.

[0133] S22. When the first wheel of the target axle slips, calculate the second target torque of the target axle based on the first target torque requirement of the target axle and the maximum allowable driving torque of each wheel corresponding to the target axle.

[0134] It should be understood that the second target required torque of the target axle is the required torque of the target axle limited by the maximum permissible drive torque, with the first wheel and the second wheel located on the target axle.

[0135] In one possible implementation, the maximum permissible drive torque of the first wheel and the maximum permissible drive torque of the second wheel are added together to obtain the cumulative maximum permissible drive torque. Then, the minimum value between the first target required torque of the target axle and the cumulative maximum permissible drive torque is determined as the second target required torque of the target axle.

[0136] It should be understood that, for the target axle, the target torque requirement must be less than the sum of the maximum permissible drive torques of the left and right wheels, and also less than the first target torque requirement allocated to the target axle during the initial torque distribution. Therefore, the minimum value between these two can be determined as the second target torque requirement for the target axle.

[0137] Based on Figure 4, Figure 5 is a schematic diagram of a scenario where the right rear wheel of a vehicle is stuck. As shown in Figure 5, the right rear wheel of the vehicle is stuck in a mud pit. At this time, the first wheel of the vehicle is the right rear wheel, the second wheel is the left rear wheel, and the target axle is the rear axle.

[0138] Based on Figure 5, the second target torque requirement for the target axle can be calculated using the following formula:

[0139] in, The second target torque requirement for the rear axle is The primary target torque requirement for the rear axle. This represents the maximum permissible drive torque for the left rear wheel. This is the maximum permissible drive torque for the right rear wheel.

[0140] S23. If the second wheel meets the preset conditions, then calculate the second target torque of each wheel corresponding to the target axle based on the second target torque requirement of the target axle, the torque capacity of the EDS, the first target torque of each wheel corresponding to the target axle, and the maximum available torque of the motor.

[0141] Among them, the preset conditions are related to the second target torque requirement of the target axle.

[0142] For example, the preset conditions include that the maximum available torque of the motor of the second wheel is less than the second target requirement of the target axle, and the second target requirement of the target axle is less than the maximum allowable drive torque of the second wheel.

[0143] It should be understood that the second target torque for each wheel corresponding to the target axle is the target torque calculated using differential torque.

[0144] In one possible implementation, the difference between the second target torque required by the target axle and the first target torque of the second wheel can be determined as the first torque difference of the first wheel. Then, the minimum value among the first torque difference of the first wheel, the torque capacity of the EDS, and the maximum available torque of the motor of the first wheel is determined as the second target torque of the first wheel. Next, the difference between the second target torque required by the target axle and the second target torque of the first wheel is determined as the first torque difference of the second wheel, and further, the minimum value among the first torque difference of the second wheel, the torque capacity of the EDS, and the maximum available torque of the motor of the second wheel is determined as the second target torque of the second wheel.

[0145] In this scheme, the target torque for each wheel needs to be less than the torque capacity of the EDS and less than the maximum available torque of the motor of the first wheel. Therefore, for the slipping wheel, the difference between the second target torque required by the target axle and the first target torque of the high-attachment side wheel can be calculated. This difference is then compared with the torque capacity of the EDS and the maximum available torque of the motor of the slipping wheel, and the minimum value is determined as the second target torque of the slipping wheel. Based on this, the difference between the second target torque required by the target axle and the second target torque of the slipping wheel is calculated again, and this difference is compared with the torque capacity of the EDS and the maximum available torque of the motor of the slipping wheel, and the minimum value is determined as the second target torque of the high-attachment side wheel. In this way, it can be ensured that the high-attachment side wheel can maximize the use of the torque that the slipping wheel cannot utilize, improve the power utilization rate, and also avoid vehicle damage and loss of control caused by excessive vehicle torque exceeding the torque capacity of the EDS or the maximum available torque of the wheel motor.

[0146] For example, based on Figure 5, and taking the right rear wheel as the first wheel as an example, the second target torque of the first wheel and the second target torque of the second wheel can be calculated using the following formulas:

[0147] in, The second target torque for the right rear wheel. The first target torque for the left rear wheel, T EDS For the torque capacity of EDS, T RRmax T represents the maximum available torque of the motor on the right rear wheel. RL_dif The second target torque for the left rear wheel, T RLmax This represents the maximum available torque for the motor on the left rear wheel.

[0148] It should be understood that the torque capacity of EDS can be calculated based on the differential lock torque model, temperature model, state correction model, and differential lock speed.

[0149] Optionally, if the second wheel meets preset conditions, the EDS is controlled to enter the locking mode.

[0150] It should be understood that after EDS enters the lock-up mode, it will use the torque capacity of EDS to redistribute the power to the two wheels of the target axle, that is, to redetermine the final motor target torque requested by the two wheels of the target axle.

[0151] S24. For each wheel corresponding to the target axle, determine the final target torque of the wheel based on the wheel's second target torque, the initial target torque requested by the motor, the yaw torque, and the available torque of the motor after power limiting the wheel.

[0152] The initial target motor torque is the target motor torque obtained after wheel slip control. Specifically, when wheel slippage is detected, wheel slip control is activated to limit the torque output of the first wheel to prevent wheel spinning, thereby obtaining the initial target motor torque of the first wheel and the initial target motor torque of the second wheel.

[0153] In one possible implementation, the minimum value among the second target torque of the first wheel, the initial target requested torque of the motor, the yaw torque, and the available torque of the motor after power limiting the first wheel can be determined as the final target requested torque of the motor for the first wheel. Alternatively, the minimum value among the second target torque of the second wheel, the initial target requested torque of the motor, the yaw torque, and the available torque of the motor after power limiting the second wheel can be determined as the final target requested torque of the motor for the second wheel.

[0154] In this implementation, the final target torque requested by the motor of the wheel is determined by comprehensively considering yaw limit and system capability limit (battery power, thermal management, fault status, etc.) to ensure that the vehicle is not damaged or loses control due to excessive torque.

[0155] For example, based on Figure 5, and continuing with the explanation using the right rear wheel as the first wheel, the final target motor torque of the first wheel and the final target motor torque of the second wheel can be calculated using the following formula: T Req_RL =Min(T) RL_dif T RL_slip T RL_yaw T RL_Power ) T Req_RR =Min(T) RR_dif T RR_slip T RR_yaw T RR_Power )

[0156] Among them, T Req_RL For the final motor target torque request of the left rear wheel, T RL_slip The initial motor target torque requested for the left rear wheel, T RL_yaw T represents the yaw torque of the left rear wheel. RL_Power T represents the available torque of the motor after power limiting the left rear wheel. Req_RR The final motor target torque requested for the right rear wheel, T RR_slip The initial motor target torque requested for the right rear wheel, T RR_yaw T represents the yaw torque of the right rear wheel. RR_Power Available torque of the motor after power limiting the right rear wheel.

[0157] The distributed drive torque distribution method provided in this application, when the vehicle's driving mode is in escape mode, determines the first target demand torque of the target axle equipped with EDS, the first target torque of each wheel corresponding to the target axle, and the maximum allowable driving torque based on the accelerator pedal opening and overall vehicle state parameters. Then, when the first wheel of the target axle slips, the second target demand torque of the target axle is calculated based on the first target demand torque of the target axle and the maximum allowable driving torque of each wheel corresponding to the target axle. If the second wheel meets preset conditions, the second target torque of each wheel corresponding to the target axle is calculated based on the second target demand torque of the target axle, the torque capacity of the EDS, the first target torque of each wheel corresponding to the target axle, and the maximum available torque of the motor. For each wheel corresponding to the target axle, the final motor target demand torque of the wheel is determined based on the wheel's second target torque, the initial motor target demand torque, the yaw torque, and the available motor torque after power limiting the wheel. The initial motor target demand torque is the motor target demand torque obtained after wheel slip control, and the preset conditions are related to the second target demand torque of the target axle, with the second wheel positioned on the target axle. In this technical solution, when the first wheel of the target axle slips and the second wheel meets the preset conditions, the EDS is controlled to enter the locking mode so that the unusable motor torque capacity of the first wheel can be transferred to the second wheel, thereby ensuring that the power is maximized.

[0158] Optionally, in some embodiments, if the wheels of the target axle exit wheel slip control, or the vehicle's reference speed is greater than a preset speed, or the vehicle's steering angle is greater than a preset angle, or any motor of the vehicle malfunctions, the EDS is controlled to exit the lock-up mode.

[0159] In this implementation, when the target axle's wheels disengage from wheel slip control, or the vehicle's reference speed exceeds a preset speed, or the vehicle's steering angle exceeds a preset angle, it indicates that the vehicle is not trapped, and the locking mode can be exited. Since the vehicle's control system is designed based on the assumption that all motors are operating normally, if one motor fails, the control system may not be able to effectively support the locking mode. Therefore, when any motor in the vehicle fails, the EDS needs to be controlled to exit the locking mode to ensure that the control system can accurately control the vehicle and guarantee its normal operation.

[0160] Optionally, in some embodiments, a control signal can be sent to the motor controller of each wheel based on the final motor target requested torque of each wheel corresponding to the target axle.

[0161] After determining the final target motor torque for each wheel according to the steps described above, the vehicle controller can send the final target motor torque for each wheel to the corresponding motor controller to control the motor and complete the torque distribution and control process.

[0162] Figure 6 is a flowchart illustrating Embodiment 2 of the distributed drive torque distribution method provided in this application. As shown in Figure 6, S21 can be implemented through the following steps:

[0163] S61. For each wheel corresponding to the target axle, calculate the wheel's utilization adhesion coefficient and slip ratio based on the vehicle speed, wheel speed, vertical load, and driving force.

[0164] In one possible implementation, the wheel slip ratio can be calculated based on the vehicle speed and wheel speed. Then, the wheel's coefficient of adhesion can be calculated based on the wheel's driving force and vertical load.

[0165] In one specific implementation, wheel speed sensors can be used to collect the wheel speed of each wheel. For each wheel corresponding to the target axle, the converted wheel speed is calculated based on the reference vehicle speed. Then, based on the converted wheel speed and the collected wheel speed, the slip ratio of that wheel is calculated. The reference vehicle speed is the vehicle speed itself.

[0166] Based on Figure 5, the slip ratio of each wheel corresponding to the target axle can be calculated using the following formula:

[0167] V Wl_RL V represents the wheel speed of the left rear wheel. Wl_RR V represents the wheel speed of the right rear wheel. x For reference vehicle speed, d r This indicates the rear wheel track width.

[0168] S RL The slip ratio of the left rear wheel, V RL The wheel speed of the left rear wheel, collected by the wheel speed sensor; S RR The slip ratio of the right rear wheel, V RR The wheel speed of the right rear wheel is collected by the wheel speed sensor.

[0169] Furthermore, the coefficient of adhesion for each wheel corresponding to the target axle is calculated using the following formula:

[0170] μ RL For the left rear wheel, the coefficient of adhesion, F x,RL For the driving force of the left rear wheel, F z,RL The vertical load on the left rear wheel; μRR For the right rear wheel, the coefficient of adhesion, F x,RR For the driving force of the right rear wheel, F z,RR This represents the vertical load on the right rear wheel.

[0171] S62. Based on the accelerator pedal opening, the vehicle's basic parameters, the input axle load / wheel load parameters, the tire rolling radius of each wheel, the wheel track, the distance from the center of gravity to the axle where the wheel is located, and the wheel's turning angle, calculate the first target torque required for the target axle and the first target torque for each wheel corresponding to the target axle.

[0172] In one possible implementation, it can be achieved through the following steps A1-A4:

[0173] Step A1: Based on the vehicle's overall basic parameters and accelerator pedal opening, determine the vehicle's total target torque requirement and total target yaw torque.

[0174] In this step, when the vehicle controller needs to distribute the vehicle's torque, it first needs to obtain the vehicle's basic parameters. Based on these parameters and the accelerator pedal opening, it determines the vehicle's total target torque requirement and total target yaw torque.

[0175] In specific implementations, the allocation of vehicle torque can be executed by the vehicle controller, specifically by the integrated distributed control unit. This unit obtains basic vehicle parameters from the vehicle controller (VCU), such as driver-demanded torque, gear position signal, vehicle longitudinal acceleration Ax, vehicle lateral acceleration Ay, vehicle yaw rate, battery power, and battery state of charge (SOC). Then, in the software model environment, it estimates a series of state parameters based on the basic vehicle parameters and accelerator pedal opening (vehicle speed estimation, axle load estimation, road surface adhesion coefficient estimation, actual yaw torque estimation, center of gravity sideslip angle estimation, etc.). Finally, it calculates the total target demand torque and the total target yaw torque, allocates them to the four drive motors, and simultaneously monitors the actual torque, actual speed, current mode, fault information, and other statuses of the four drive motors.

[0176] Step A2: Calculate the torque distribution ratio of the target axle based on the input axle load / wheel load parameters.

[0177] The vehicle's axle load / wheel load parameters include the front axle wheel load, the rear axle wheel load, and the total wheel load. These parameters can be obtained from the upper-level module. Specifically, the sum of the wheel loads of the two front wheels is the front axle wheel load, and the sum of the wheel loads of the two rear wheels is the rear axle wheel load.

[0178] In the specific implementation of this step, the torque distribution ratio of the target axle can be obtained by the ratio of the wheel load corresponding to the target axle to the total wheel load.

[0179] Step A3: Calculate the yaw torque conversion coefficient of each wheel based on the tire rolling radius, wheel track, distance from the center of gravity to the wheel axle, and wheel rotation angle of each wheel corresponding to the target axle.

[0180] For each wheel, the yaw torque conversion coefficient can be calculated by combining the wheel's own characteristics. This yaw torque conversion coefficient is used to represent the coefficient that converts the drive torque into yaw torque, and is used to calculate the requested torque for each wheel during the torque distribution process.

[0181] Based on Figure 5, the yaw torque conversion coefficient of the first wheel and the yaw torque conversion coefficient of the second wheel can be calculated using the following formula: λ RL =[sin(α) RL )×l r -cos(α RL )×d / 2)] / R rolling λ RR =[sin(α) RR )×l r +cos(α RR )×d / 2)] / R rolling

[0182] Where, λ RL α is the yaw torque conversion coefficient for the left rear wheel. RL It's the left rear wheel steering angle, l r It is the distance from the center of gravity to the rear axle, d is the wheel track, and R is the distance from the center of gravity to the rear axle. rolling It is the rolling radius of the wheel / tire, α RR It is the right rear wheel steering angle, α RR It's the right rear wheel's turning angle.

[0183] Step A4: Based on the total target torque demand, the total target yaw torque, the torque distribution ratio of the target axle, and the yaw torque conversion coefficient of each wheel corresponding to the target axle, calculate the first target torque demand of the target axle and the first target torque of each wheel corresponding to the target axle.

[0184] Based on Figure 5, the first target torque requirement of the target axle can be calculated using the following formula: T Re_TgtDrv =T TgtDriving ×Rate

[0185] Among them, T TgtDriving It represents the total target torque requirement, while Rate is the torque distribution ratio to the rear axle.

[0186] Furthermore, the yaw torque of the target axle can be calculated using the following formula: T RE_Yaw =T TgtYaw ×Rate

[0187] Among them, T RE_Yaw It is the rear axle yaw torque, T TgtYaw It is the overall target yaw torque.

[0188] Furthermore, the first target torque requirement for the target axle and the first target torque for each wheel corresponding to the target axle can be calculated using the following formulas: T RL_raw =(T TgtDriving ×λ RR -T RE_Yaw ) / (λ RR -λ RL ); T RR_raw =(T TgtDriving ×λ RL -T RE_Yaw ) / (λ rl -λ RR );

[0189] Among them, T RL_raw The first target torque for the left rear wheel, T RR_raw The first target torque for the right rear wheel.

[0190] S63. Based on the road surface type, the wheel's coefficient of adhesion, slip ratio, preset maximum load, tire rolling radius, and safety factor, determine the wheel's permissible maximum driving torque. The safety factor is determined based on the coefficient of adhesion.

[0191] In one possible implementation, it can be achieved through the following steps B1-B3:

[0192] Step B1: Determine the target slip ratio corresponding to the road surface type.

[0193] Figure 7 is a graph showing the relationship between slip ratio and coefficient of adhesion provided in the embodiments of this application. As shown in Figure 7, the coefficient of adhesion for the same slip ratio is different in different road surface types (concrete pavement, dry asphalt pavement, wet asphalt pavement, snow and ice), and the coefficient of adhesion first increases and then decreases as the slip ratio increases.

[0194] Therefore, based on the current road surface type on which the vehicle is traveling, the target slip ratio corresponding to that current road surface type can be determined. The target slip ratio is the slip ratio corresponding to the maximum utilization coefficient of adhesion under that road surface type. Subsequently, based on this target slip ratio and the slip ratio of the wheels, the utilization coefficient limit of the road surface where the wheels are located can be determined.

[0195] Step B2: Determine the maximum permissible driving force of the wheel based on the wheel slip ratio, target slip ratio, coefficient of adhesion, and preset maximum load.

[0196] The wheel slip ratio can be compared with the target slip ratio. If the wheel slip ratio is greater than or equal to the target slip ratio, the coefficient of adhesion corresponding to the target slip ratio is determined as the limit of the coefficient of adhesion. If the wheel slip ratio is less than the target slip ratio, the coefficient of adhesion of the wheel is determined as the limit of the coefficient of adhesion.

[0197] Based on Figure 5, the maximum permissible driving force for each wheel corresponding to the target axle can be calculated using the following formula:

[0198] in, The maximum permissible driving force for the left rear wheel. The maximum ground adhesion for the left rear wheel. For the preset maximum load on the left rear wheel, μ RL_max To utilize the adhesion coefficient limit of the left rear wheel, This is the maximum permissible driving force for the right rear wheel. The maximum ground adhesion for the right rear wheel. For the preset maximum load on the right rear wheel, μ RR_max This represents the limit of the adhesion coefficient utilized by the right rear wheel.

[0199] In practical applications, the maximum ground adhesion of the wheel is generally determined as the maximum permissible driving force.

[0200] Step B3: Determine the maximum allowable driving torque of the wheel based on the maximum allowable driving force of the wheel, the tire rolling radius, and the safety factor.

[0201] Based on Figure 5, the maximum permissible driving torque for each wheel corresponding to the target axle can be calculated using the following formula:

[0202] R is the maximum permissible drive torque for the left rear wheel. roll η is the tire rolling radius. μRL For the safety factor of the left rear wheel, η is the maximum permissible drive torque for the right rear wheel. μRR This is the safety factor for the right rear wheel.

[0203] It should be understood that the safety factor of each wheel is obtained by looking up a table using the adhesion coefficient limit.

[0204] In the distributed drive off-road traction mode (traction mode), the vehicle can significantly improve its passability and stability in complex road conditions through intelligent torque distribution strategies. The torque distribution process typically follows these steps:

[0205] 1) Sensor data processing: Based on the signals from on-board sensors (including but not limited to wheel speed sensors, accelerometers and steering angle sensors), the vehicle status and road surface type are calculated in real time.

[0206] 2) Target torque calculation: Based on the vehicle's basic parameters and current driving conditions, the controller calculates the total target torque requirement and the total target yaw torque, ensuring that the vehicle can not only move forward but also maintain a stable driving direction.

[0207] 3) Torque Distribution: Based on axle load / wheel load parameters and the total target torque requirement, the controller will determine the specific torque value that each wheel should receive. For wheels on low-traction surfaces, power output may be reduced or even temporarily cut off to prevent slippage; while for other wheels with sufficient traction, torque supply will be increased to maintain vehicle power and stability.

[0208] 4) Dynamic adjustment: During driving, based on vehicle needs and road conditions, the controller will continuously monitor and dynamically adjust the torque distribution of each wheel to cope with constantly changing road conditions and driving needs, and dynamically adjust the torque output of the front and rear axle motors to optimize system efficiency and vehicle stability.

[0209] 5) System optimization: In order to further improve performance, the distributed drive system may also combine preset constraints and objective functions to achieve more refined control effects through optimization algorithms.

[0210] Through the above process, the distributed drive wheels can demonstrate excellent power, stability and economy in off-road mode, giving full play to their advantages in driving force output and handling stability.

[0211] Next, we will introduce mechanical differential locks and electronic differential locks separately:

[0212] Mechanical Differential Lock: Figure 8 shows a structural diagram of a traditionally powered off-road vehicle. As shown in Figure 8, a traditionally powered off-road vehicle has only one power source (longitudinal engine), which is connected to a transfer case to distribute the power output of the longitudinal engine to different axles of the vehicle (such as the front and rear axles). The mechanical differential lock of this off-road vehicle is located on the rear axle. The function of this mechanical differential lock is to eliminate the wheel speed difference between the left and right drive wheels to obtain the same driving force. After locking, it cancels the automatic distribution of driving force relying on rolling resistance. When the front, center, and rear differential locks are all locked, the power will be distributed in a fixed ratio of 50%:50% front to rear and 50%:50% left to right. The vehicle can travel in a straight line at low speeds, but when turning, the left and right wheels can only forcibly twist and slide. Steering can only be achieved by relying on manual torque steering or adding a special power steering mechanism. Experience is used to compensate for the limitations of the mechanical structure, resulting in a very poor actual driving experience. Traditional mechanical four-wheel drive off-road vehicles have a high rate of loss of control and pose safety risks. For example: Assume the vehicle's total power is 100. With all three differential locks engaged, the power distribution is 50% for the front axle, 50% for the rear axle, 25% for the left front wheel, 25% for the right front wheel, 25% for the left rear wheel, and 25% for the right rear wheel. If a wheel on one axle slips, the power distribution between the slipping wheel and the wheel on the higher-tethered side of that axle is approximately 0:50%.

[0213] Electronic differential lock: It automatically engages the lock by judging the speed difference between the left and right wheels. This automatic locking method is determined by the electronic differential lock itself and has no direct interaction with the yaw stability control and anti-slip control of the TVC module. If the control target torque deviates greatly, it may cause power loss and poor vehicle driving stability.

[0214] In summary, traditional electronic differential mechanisms do not interact with wheel anti-slip control, resulting in large deviations in the control target torque and failing to maximize the vehicle's driving capabilities and drivability.

[0215] The distributed drive torque distribution method provided in this application retains the characteristics of distributed drive torque control, realizes intelligent transfer of drive torque, can make full use of the maximum capacity of the drive system, and improve the vehicle's extreme extrication ability under special working conditions.

[0216] Next, we will explain the torque distribution scheme of distributed drive through two specific examples.

[0217] Figure 9 is a flowchart illustrating a third embodiment of the distributed drive torque distribution method provided in this application. As shown in Figure 9, the distributed drive torque distribution method includes the following steps:

[0218] S901, Obtain the driver's confirmation operation via HMI.

[0219] This determination operation includes a determination operation for ATS or a determination operation for 4L.

[0220] S902. Based on the determined operation, determine the mode determined by the driver.

[0221] S903 monitors the status of the electric drive system and obtains the motor mode, actual speed, actual torque, and fault level.

[0222] S904. Determine the electric drive system capability based on the motor mode, actual speed, actual torque, and fault level to output left rear wheel torque limit and right rear wheel torque limit.

[0223] S905. Determine the vehicle status parameters.

[0224] The vehicle status parameters include actual vehicle speed, actual wheel speed, actual torque, and inertial measurement unit (IMU) sensor parameters.

[0225] S906. Calculate the coefficient of adhesion for each wheel based on the overall vehicle condition parameters.

[0226] Specifically, the coefficient of friction of the left front wheel, the coefficient of friction of the left front wheel, the coefficient of friction of the right rear wheel, and the coefficient of friction of the right rear wheel are calculated.

[0227] S907: Calculate the target torque requirement based on the driver's selected mode, left rear wheel torque limit, and right rear wheel torque limit.

[0228] S908. Wheel slip ratio control is performed based on the coefficient of friction of the left front wheel, the coefficient of friction of the left front wheel, the coefficient of friction of the right rear wheel, and the coefficient of friction of the right rear wheel.

[0229] S909. Calculate the EDS torque based on the EDS status, EDS location, and EDS torque capacity.

[0230] S910 performs torque distribution under PID control based on the target torque of the front axle, the original target torque of the left rear wheel, the original target torque of the right rear wheel, the torque reduction request of the left rear wheel, the torque reduction request of the right rear wheel, the torque capacity of the left rear wheel, the torque capacity of the right rear wheel, and the maximum torque of the EDS.

[0231] S911. Based on the torque limit, speed limit, power limit calculated by EDS torque and the yaw torque limit, steering input limit, front axle target torque, left rear wheel target torque, and right rear wheel target torque obtained by PID control torque distribution, perform torque arbitration, torque limit, and torque transfer to obtain the arbitration-adjusted front axle target torque, the arbitration-adjusted right rear wheel target torque, and the arbitration-adjusted right and left wheel target torque.

[0232] Figure 10 is a flowchart illustrating Embodiment 4 of the distributed drive torque distribution method provided in this application. As shown in Figure 10, the distributed drive torque distribution method includes the following steps:

[0233] S1001, HMI input.

[0234] S1002, Determine the enabling status of the driving mode.

[0235] If ATS is enabled, execute S1003; if 4L is enabled, execute S1010.

[0236] S1003. Calculate the required torque for the first target based on the terrain pattern.

[0237] S1004. Determine if the right rear wheel is slipping.

[0238] If the right rear wheel slips, execute S1005; if the right rear wheel does not slip, execute S1003.

[0239] S1005, Is the maximum available torque of the motor of the left rear wheel less than the second target requirement of the rear axle?

[0240] If so, then execute S1006.

[0241] S1006, Is the second target requirement of the rear axle less than the maximum permissible drive torque of the left rear wheel?

[0242] If yes, then execute S1007; otherwise, adjust the EDS status to open.

[0243] S1007. Adjust the EDS status to Sliplock.

[0244] S1008, Determine the final motor target requested torque for the left and right rear wheels.

[0245] S1009. Determine whether EDS is enabled.

[0246] If yes, and EDS is in a locked state, then execute S1008; if yes, and EDS is in a locked state, then execute S1010; otherwise, execute S1002.

[0247] S1010. Distribute the target torque according to a 50:50 ratio to determine the target torque requested by the motors of the left and right rear wheels.

[0248] In the aforementioned technical solution, by acquiring vehicle load information and road condition information of the target vehicle, in the escape mode and when the accelerator pedal is depressed, the target torque of the differential lock is obtained based on the pedal opening information, vehicle load information, and road condition information, and the target position of the differential lock is determined based on the target torque. The amount of torque transferred is the "target torque of EDS," a value dynamically calculated by the vehicle control system based on the current vehicle status, road conditions, and driving needs, aiming to maximize the vehicle's traction and stability under complex road conditions.

[0249] This technical solution locks the EDS (Electronic Speed ​​Controller) when it detects wheel slippage and the calculated target driving force exceeds the maximum motor torque capacity of a single wheel. It calculates the torque difference between the target driving torque of the target axle and the maximum motor torque capacity of a single wheel. Based on this calculated torque difference, it controls the torque transmission capability of the EDS. It determines whether the vehicle has escaped the stalemate based on the slip ratio of the slipping wheel and then exits slip ratio control. Based on the vehicle's escape status, it controls the EDS to open, restoring the road driving force to the slipping wheel. Intelligent distribution: When one wheel slips and the required torque is greater than the motor torque of the non-slipping side (allowable motor torque, motor torque limited), and the slipping side motor has no capacity-limited fault, the limited-slip differential lock intelligently locks to compensate for the driving torque.

[0250] The technical effects of this technical solution include:

[0251] 1) Coaxial distributed dual motors with electromechanical limited slip differential lock to achieve locking of left and right motor drive.

[0252] 2) The intelligent escape mode determines the opening and closing of the electronic limited-slip differential lock and the torque output based on the wheel slip ratio.

[0253] 3) Transfer the motor torque capacity of the slipping wheel to the high-attachment wheel to increase the total driving torque capacity of the coaxial wheel, maximize the use of the coaxial driving capacity, and help the vehicle get out of trouble.

[0254] 4) The interaction between electronic differential control and wheel slip control (state) can accurately calculate the actual required driving torque, making the vehicle driving process more stable.

[0255] The above is a detailed description of the preferred embodiments of this application, but this application is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

[0256] The following are embodiments of the apparatus described in this application, which can be used to execute the embodiments of the method described in this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method described in this application.

[0257] Figure 11 is a schematic diagram of the structure of the distributed drive torque distribution control device provided in an embodiment of this application. As shown in Figure 11, the distributed drive torque distribution control device 110 includes:

[0258] The first determining module 1101 is configured to determine the first target required torque of the target axle with EDS, the first target torque of each wheel corresponding to the target axle, and the maximum allowable driving torque based on the accelerator pedal opening and the overall vehicle status parameters when the vehicle's driving mode is in the escape mode.

[0259] The first calculation module 1102 is configured to calculate the second target torque of the target axle based on the first target torque requirement of the target axle and the maximum allowable driving torque of each wheel corresponding to the target axle when the first wheel of the target axle slips.

[0260] The second calculation module 1103 is configured to calculate the second target torque of each wheel corresponding to the target axle based on the second target required torque of the target axle, the torque capacity of the EDS, the first target torque of each wheel corresponding to the target axle, and the maximum available torque of the motor if the second wheel meets the preset conditions. The preset conditions are related to the second target required torque of the target axle, and the second wheel is located on the target axle.

[0261] The second determining module 1104 is configured to determine the final motor target requested torque of each wheel corresponding to the target axle based on the wheel's second target torque, the initial motor target requested torque, the yaw torque, and the motor's available torque after power limiting the wheel. The initial motor target requested torque is the motor target requested torque obtained after wheel slip control.

[0262] In one possible design, the first computing module 1102 is specifically configured as follows:

[0263] Add the maximum allowable driving torque of the first wheel to the maximum allowable driving torque of the second wheel to obtain the sum of the maximum allowable driving torques;

[0264] The minimum value between the first target required torque and the maximum permissible drive torque of the target axle is determined as the second target required torque of the target axle.

[0265] In one possible design, the second computing module 1103 is specifically configured as follows:

[0266] The difference between the second target torque required for the target axle and the first target torque of the second wheel is determined as the first torque difference of the first wheel.

[0267] The minimum value among the first torque difference of the first wheel, the torque capacity of the EDS, and the maximum available torque of the motor of the first wheel is determined as the second target torque of the first wheel.

[0268] The difference between the second target torque required for the target axle and the second target torque of the first wheel is determined as the first torque difference of the second wheel.

[0269] The minimum value among the first torque difference of the second wheel, the torque capacity of the EDS, and the maximum available torque of the motor of the second wheel is determined as the second target torque of the second wheel.

[0270] In one possible design, the second determining module 1104 is specifically configured as follows:

[0271] The minimum value among the second target torque of the first wheel, the initial target torque requested by the motor, the yaw torque, and the available torque of the motor after power limiting the first wheel is determined as the final target torque requested by the motor of the first wheel.

[0272] The minimum value among the second target torque of the second wheel, the initial target torque requested by the motor, the yaw torque, and the available torque of the motor after power limiting the second wheel is determined as the final target torque requested by the motor of the second wheel.

[0273] In one possible design, the first determining module 1101 is specifically configured as follows:

[0274] For each wheel corresponding to the target axle, the wheel's utilization adhesion coefficient and slip ratio are calculated based on the vehicle speed, wheel speed, vertical load, and driving force.

[0275] Based on the accelerator pedal opening, the vehicle's basic parameters, the input axle load / wheel load parameters, the tire rolling radius of each wheel, the wheel track, the distance from the center of gravity to the axle where the wheel is located, and the wheel's turning angle, calculate the first target torque required for the target axle and the first target torque for each wheel corresponding to the target axle.

[0276] The maximum permissible driving torque of the wheel is determined based on the road surface type, the wheel's coefficient of adhesion, slip ratio, preset maximum load, tire rolling radius, and safety factor. The safety factor is determined based on the coefficient of adhesion.

[0277] In one possible design, the first determining module 1101 is specifically configured as follows:

[0278] Calculate the wheel slip ratio based on the vehicle speed and wheel speed.

[0279] The coefficient of adhesion of the wheel is calculated based on the driving force and vertical load of the wheel.

[0280] In one possible design, the first determining module 1101 is specifically configured as follows:

[0281] Based on the vehicle's overall basic parameters and accelerator pedal opening, determine the vehicle's total target torque requirement and total target yaw torque.

[0282] Calculate the torque distribution ratio of the target axle based on the input axle load / wheel load parameters;

[0283] The yaw torque conversion coefficient of the wheel is calculated based on the tire rolling radius, wheel track, distance from the center of gravity to the wheel axle of each wheel corresponding to the target axle, and the wheel's turning angle.

[0284] Based on the total target torque demand, the total target yaw torque, the torque distribution ratio of the target axle, and the yaw torque conversion coefficient of each wheel corresponding to the target axle, calculate the first target torque demand of the target axle and the first target torque of each wheel corresponding to the target axle.

[0285] In one possible design, the first determining module 1101 is specifically configured as follows:

[0286] Based on the road surface type, determine the target slip ratio corresponding to the road surface type. The target slip ratio is the slip ratio corresponding to the maximum utilization coefficient of adhesion for the road surface type.

[0287] The allowable maximum driving force of the wheel is determined based on the wheel slip ratio, target slip ratio, coefficient of adhesion, and preset maximum load.

[0288] The maximum allowable driving torque of a wheel is determined based on its maximum allowable driving force, tire rolling radius, and safety factor.

[0289] In one possible design, the distributed drive torque distribution control device 110 further includes a control module configured as follows:

[0290] If the second wheel meets the preset conditions, control the EDS to enter the locking mode;

[0291] If the target axle's wheel exits wheel slip control, or the vehicle's reference speed exceeds the preset speed, or the vehicle's steering angle exceeds the preset angle, or any of the vehicle's motors malfunctions, the EDS will exit the lock-up mode.

[0292] In one possible design, the preset conditions include that the maximum available torque of the motor of the second wheel is less than the second target requirement of the target axle, and the second target requirement of the target axle is less than the maximum permissible drive torque of the second wheel.

[0293] In one possible design, the distributed drive torque distribution control device 110 further includes an adjustment module configured as follows:

[0294] In response to the user's selection of the obstacle avoidance mode through the human-machine interface (HMI), the vehicle's driving mode is adjusted to obstacle avoidance mode.

[0295] In one possible design, the distributed drive torque distribution control device 110 further includes a transmitting module, configured as follows:

[0296] Based on the final motor target torque requested by each wheel corresponding to the target axle, a control signal is sent to the motor controller of each wheel.

[0297] The distributed drive torque distribution control device provided in this application embodiment can be used to execute the distributed drive torque distribution control method in any of the above embodiments. Its implementation principle and technical effect are similar, and will not be described again here.

[0298] It should be noted that the division of the various modules in the above device is merely a logical functional division. In actual implementation, they can be fully or partially integrated into a single physical entity, or they can be physically separated. Furthermore, these modules can be implemented entirely in software via processing element calls; they can be fully implemented in hardware; or some modules can be implemented in software via processing element calls, while others are implemented in hardware. Additionally, these modules can be fully or partially integrated together, or implemented independently. The processing element here can be an integrated circuit with signal processing capabilities. During implementation, each step of the above method or each of the above modules can be completed through the integrated logic circuits in the hardware of the processor element or through software instructions.

[0299] In addition, this application also provides a vehicle, which includes a vehicle body, a vehicle controller, a motor for each wheel, a memory, and computer program instructions stored in the memory and executable on the vehicle controller. When the vehicle controller executes the computer program instructions, it implements the technical solution of the distributed drive torque distribution method in any of the foregoing method embodiments.

[0300] Optionally, the various devices mentioned above in the vehicle can be connected via a system bus.

[0301] The memory can be a separate storage unit or a storage unit integrated into the vehicle controller.

[0302] Optionally, the vehicle may also include interfaces for interacting with other devices and displays for showing information to the user.

[0303] It should be understood that the vehicle controller can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this application can be directly manifested as being executed by a hardware processor, or executed by a combination of hardware and software modules within the processor.

[0304] The system bus can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The system bus can be divided into address bus, data bus, control bus, etc. For ease of representation, only one thick line is used in the diagram, but this does not indicate that there is only one bus or one type of bus. Memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage device.

[0305] All or part of the steps in the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a readable memory. When the program is executed, it performs the steps of the above method embodiments; and the aforementioned memory (storage medium) includes: read-only memory (ROM) and RAM.

[0306] The vehicle provided in this application embodiment is used to execute the technical solution provided in any method embodiment. Its implementation principle and technical effect are similar, and will not be repeated here.

[0307] This application provides a computer-readable storage medium storing computer-executable instructions. When these instructions are executed on the vehicle controller, the vehicle performs the aforementioned distributed drive torque distribution method.

[0308] The aforementioned computer-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory, electrically erasable programmable read-only memory, erasable programmable read-only memory, programmable read-only memory, read-only memory, magnetic storage, and flash memory. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0309] Optionally, a readable storage medium can be coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Alternatively, the readable storage medium can be an integral part of the processor. Both the processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components within the device.

[0310] This embodiment also provides a chip, which includes a memory and a vehicle controller. The memory stores code and data and is coupled to the vehicle controller. The vehicle controller runs the program in the memory so that the chip can be used to execute the above-mentioned distributed drive torque distribution method.

[0311] This embodiment also provides a computer program, which, when executed by the vehicle controller, is used to perform the aforementioned distributed drive torque distribution method.

[0312] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A distributed drive torque distribution method, comprising: When the vehicle's driving mode is in the escape mode, the first target required torque of the target axle equipped with the electronic limited-slip differential (EDS), the first target torque of each wheel corresponding to the target axle, and the maximum allowable driving torque are determined based on the accelerator pedal opening and the vehicle's status parameters. When the first wheel of the target axle slips, the second target torque of the target axle is calculated based on the first target torque requirement of the target axle and the maximum allowable driving torque of each wheel corresponding to the target axle. If the second wheel meets the preset conditions, then the second target torque of each wheel corresponding to the target axle is calculated based on the second target required torque of the target axle, the torque capacity of the EDS, the first target torque of each wheel corresponding to the target axle, and the maximum available torque of the motor. The preset conditions are related to the second target required torque of the target axle, and the second wheel is located on the target axle. For each wheel corresponding to the target axle, the final target torque of the motor for the wheel is determined based on the second target torque of the wheel, the initial target torque of the motor, the yaw torque, and the available torque of the motor after power limiting the wheel. The initial target torque of the motor is the target torque of the motor obtained after wheel slip control.

2. The method according to claim 1, wherein calculating the second target torque demand of the target axle based on the first target torque demand of the target axle and the maximum allowable driving torque of each wheel corresponding to the target axle comprises: Add the maximum allowable driving torque of the first wheel and the maximum allowable driving torque of the second wheel to obtain the sum of the maximum allowable driving torques; The minimum value between the first target required torque of the target axle and the maximum allowable driving torque is determined as the second target required torque of the target axle.

3. The method according to claim 1 or 2, wherein calculating the second target torque of each wheel corresponding to the target axle based on the second target required torque of the target axle, the torque capacity of the EDS, the first target torque of each wheel corresponding to the target axle, and the maximum available torque of the motor includes: The difference between the second target required torque of the target axle and the first target torque of the second wheel is determined as the first torque difference of the first wheel. The minimum value among the first torque difference of the first wheel, the torque capacity of the EDS, and the maximum available torque of the motor of the first wheel is determined as the second target torque of the first wheel. The difference between the second target required torque of the target axle and the second target torque of the first wheel is determined as the first torque difference of the second wheel; The minimum value among the first torque difference of the second wheel, the torque capacity of the EDS, and the maximum available torque of the motor of the second wheel is determined as the second target torque of the second wheel.

4. The method according to any one of claims 1-3, wherein determining the final target motor torque for each wheel corresponding to the target axle, based on the second target torque of the wheel, the initial target motor torque, the yaw torque, and the available motor torque after power limiting the wheel, comprises: The minimum value among the second target torque of the first wheel, the initial target torque requested by the motor, the yaw torque, and the available torque of the motor after power limiting the first wheel is determined as the final target torque requested by the motor of the first wheel. The minimum value among the second target torque of the second wheel, the initial target torque requested by the motor, the yaw torque, and the available torque of the motor after power limiting the second wheel is determined as the final target torque requested by the motor of the second wheel.

5. The method according to any one of claims 1-4, wherein determining the first target required torque of the target axle equipped with EDS, the first target torque of each wheel corresponding to the target axle, and the allowable maximum drive torque based on the accelerator pedal opening and vehicle state parameters, comprises: For each wheel corresponding to the target axle, the utilization adhesion coefficient and slip ratio of the wheel are calculated based on the vehicle speed, wheel speed, vertical load, and driving force. Based on the accelerator pedal opening, the vehicle's overall basic parameters, the input axle load / wheel load parameters, the tire rolling radius of each wheel, the wheel track, the distance from the center of gravity to the axle where the wheel is located, and the wheel's rotation angle, calculate the first target torque required for the target axle and the first target torque for each wheel corresponding to the target axle. The allowable maximum driving torque of the wheel is determined based on the road surface type, the wheel's coefficient of adhesion, slip ratio, preset maximum load, tire rolling radius, and safety factor. The safety factor is determined based on the coefficient of adhesion.

6. The method according to claim 5, wherein calculating the coefficient of adhesion and slip ratio of the wheel based on the vehicle speed, wheel speed, vertical load, and driving force comprises: Calculate the slip ratio of the wheel based on the vehicle speed and the wheel speed; The coefficient of adhesion of the wheel is calculated based on the driving force and vertical load of the wheel.

7. The method according to claim 5 or 6, wherein calculating the first target torque required for the target axle and the first target torque for each wheel corresponding to the target axle based on the accelerator pedal opening, the vehicle's basic parameters, the input axle load / wheel load parameters, the tire rolling radius of each wheel, the wheel track, the distance from the center of gravity to the axle where the wheel is located, and the wheel's rotation angle includes: Based on the vehicle's overall basic parameters and the accelerator pedal opening, determine the vehicle's total target torque requirement and total target yaw torque. Calculate the torque distribution ratio of the target axle based on the input axle load / wheel load parameters; The yaw torque conversion coefficient of the wheel is calculated based on the tire rolling radius, wheel track, distance from the center of gravity to the axle of the wheel corresponding to each wheel of the target axle, and the turning angle of the wheel. Based on the total target torque requirement, the total target yaw torque, the torque distribution ratio of the target axle, and the yaw torque conversion coefficient of each wheel corresponding to the target axle, calculate the first target torque requirement of the target axle and the first target torque of each wheel corresponding to the target axle.

8. A distributed drive torque distribution control device, comprising: The first determining module is configured to determine the first target required torque of the target axle equipped with an electronic limited-slip differential (EDS), the first target torque of each wheel corresponding to the target axle, and the maximum allowable driving torque based on the accelerator pedal opening and the overall vehicle status parameters when the vehicle's driving mode is in the escape mode. The first calculation module is configured to calculate the second target torque of the target axle when the first wheel of the target axle slips, based on the first target torque requirement of the target axle and the maximum allowable driving torque of each wheel corresponding to the target axle. The second calculation module is configured to calculate the second target torque of each wheel corresponding to the target axle based on the second target required torque of the target axle, the torque capacity of the EDS, the first target torque of each wheel corresponding to the target axle, and the maximum available torque of the motor if the second wheel meets the preset conditions. The preset conditions are related to the second target required torque of the target axle, and the second wheel is located on the target axle. The second determining module is configured to determine the final motor target requested torque of each wheel corresponding to the target axle, based on the second target torque of the wheel, the initial motor target requested torque, the yaw torque, and the available motor torque after power limiting the wheel. The initial motor target requested torque is the motor target requested torque obtained after wheel slip control.

9. A vehicle comprising: The vehicle body, the vehicle controller, the motor for each wheel, the memory, and the computer program instructions stored in the memory and executable on the vehicle controller, wherein the vehicle controller executes the computer program instructions to implement the torque distribution method of distributed drive as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing computer-executable instructions for implementing the torque distribution method of a distributed drive as described in any one of claims 1 to 7.

11. A chip comprising a memory and a vehicle controller, the memory storing code and data, the memory being coupled to the vehicle controller, the vehicle controller executing a program in the memory such that the chip is used to perform a distributed drive torque distribution method as described in any one of claims 1 to 7.

12. A computer program product, comprising: A computer program, when executed by a vehicle controller, is used to perform a torque distribution method for distributed drive as described in any one of claims 1 to 7.

13. A computer program, when executed by a vehicle controller, for performing the torque distribution method of distributed drive as described in any one of claims 1 to 7.

Images